Tonypandy · Mid Glamorgan

Extra bedroom and en-suite extensions in Tonypandy

For an extra bedroom and en-suite extension in Tonypandy, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Mid Glamorgan.

Quick reference for homeowners in Tonypandy.

Postcode districts
CF40
County / area
Mid Glamorgan, Wales
Price region
Wales
Guide price
£51,500–£69,500 (£1,840–£2,480 per m²), plus £5,500–£11,000 for the en-suite
Approval route
It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary.
Nearest towns
Rhondda (2.6 miles), Ferndale (2.7 miles), Pentre (2.7 miles)
Distance to Rhondda
about 2.6 miles
First visit
Free, no obligation

About an extra bedroom and en-suite extension

An extra bedroom and en-suite extension is a two-storey extension planned around a new double bedroom with its own shower room on the first floor, with a ground-floor room below. It is one of the most effective ways to add space for a growing family. Nationwide's 2025 research linked adding a double bedroom and bathroom to a three-bed, one-bathroom house with value gains of up to 24%.

Around Tonypandy we also work in Rhondda, Ferndale and Pentre, and across the rest of Mid Glamorgan. Postcode district in and near Tonypandy: CF40.

What it costs in Tonypandy

Our guide for Wales is £1,840–£2,480 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts an extra bedroom and en-suite extension in Tonypandy at roughly £51,500–£69,500 (plus £5,500–£11,000 for the en-suite). Keep a contingency of around 10% for things nobody can see until the ground is opened up.

SpecPer m²A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential£1,690–£2,290 per m²£47,500–£64,000
Standard£1,840–£2,480 per m²£51,500–£69,500
Premium£2,210–£2,980 per m²£62,000–£83,500

Planning and building regulations in Tonypandy

In Wales, an extra bedroom at the rear can be permitted development if the first floor goes no more than 3 m beyond the original rear wall and stays 10.5 m from the rear boundary. A two-storey side extension can also qualify if it is 10.5 m from the side boundary, set back 1 m and adds no more than 50% width. Otherwise the fee is £585.

Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.

Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).

Design points for Tonypandy homes

Escape window and fire safety

A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and high, and the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs. We design the windows to meet this.

Connecting to the landing

The new bedroom must be reached from the existing landing, usually through a new opening in the outside wall or by taking part of an existing bedroom as a corridor. We look at the stairs and landing first, because a poor connection can waste much of the new space.

How we'd run your project

  1. Visit and first ideas

    One of our team visits your house in Tonypandy, checks the walls, roof and drains, and sketches out options with you.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Tonypandy.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  4. Finish and certify

    Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about extra bedroom and en-suite extensions in Tonypandy

Do I need planning permission for an extra bedroom and en-suite extension in Tonypandy?

Tonypandy is in Wales, so Wales planning rules apply. It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How much does an extra bedroom and en-suite extension cost in Tonypandy?

Our guide for Wales, which covers Tonypandy, is £1,840–£2,480 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £51,500–£69,500 (plus £5,500–£11,000 for the en-suite). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Which postcodes do you cover around Tonypandy?

We cover Tonypandy (CF40) and nearby places including Rhondda, Ferndale and Pentre, plus the rest of Mid Glamorgan. The first site visit is free.

Does an extra bedroom add value to my house?

It usually does, though not always by the full cost. Nationwide's 2025 research found that adding a double bedroom to a two-bed house was linked to about 13% higher value, and a double bedroom and bathroom on a three-bed, one-bathroom house up to 24%. Local ceiling prices still apply.

Can an en-suite go in a room with no window?

Yes. A shower room without a window is allowed, provided it has a mechanical extract fan to the outside that meets Part F. Many people prefer a window for daylight, but if it faces a neighbour it will usually need obscure glass. We plan the extract route early so the duct is hidden.

Nearby

Nearby towns we cover for extra bedroom and en-suite extensions:

Other extensions in Tonypandy

All two-storey extension services in Tonypandy · Extra bedroom and en-suite extensions across Mid Glamorgan

The quickest next step is a visit. We'll look at your house in Tonypandy and give you an honest view of the options.

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